diff mbox

[v5,1/1] hwmon: Add support for INA3221 Triple Current/Voltage Monitors

Message ID 20160610153233.6169-2-afd@ti.com (mailing list archive)
State Accepted
Headers show

Commit Message

Andrew Davis June 10, 2016, 3:32 p.m. UTC
Add support for the the INA3221 26v capable, Triple channel,
Bi-Directional, Zero-Drift, Low-/High-Side, Current/Voltage Monitor
with I2C interface.

Signed-off-by: Andrew F. Davis <afd@ti.com>
---
 Documentation/hwmon/ina3221 |  35 ++++
 drivers/hwmon/Kconfig       |  11 ++
 drivers/hwmon/Makefile      |   1 +
 drivers/hwmon/ina3221.c     | 446 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 493 insertions(+)
 create mode 100644 Documentation/hwmon/ina3221
 create mode 100644 drivers/hwmon/ina3221.c

Comments

Guenter Roeck June 10, 2016, 4:44 p.m. UTC | #1
On Fri, Jun 10, 2016 at 10:32:33AM -0500, Andrew F. Davis wrote:
> Add support for the the INA3221 26v capable, Triple channel,
> Bi-Directional, Zero-Drift, Low-/High-Side, Current/Voltage Monitor
> with I2C interface.
> 
> Signed-off-by: Andrew F. Davis <afd@ti.com>

Applied to -next.

Can you by any chance send me a register dump ? I would like to write
module test code for the chip.

Thanks,
Guenter
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Andrew Davis June 17, 2016, 11:21 p.m. UTC | #2
On 06/10/2016 11:44 AM, Guenter Roeck wrote:
> On Fri, Jun 10, 2016 at 10:32:33AM -0500, Andrew F. Davis wrote:
>> Add support for the the INA3221 26v capable, Triple channel,
>> Bi-Directional, Zero-Drift, Low-/High-Side, Current/Voltage Monitor
>> with I2C interface.
>>
>> Signed-off-by: Andrew F. Davis <afd@ti.com>
> 
> Applied to -next.
> 
> Can you by any chance send me a register dump ? I would like to write
> module test code for the chip.
> 

No problem:

# i2cdump -y 2 0x48
No size specified (using byte-data access)
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: 18 16 80 00 08 7f 80 7f 80 00 00 00 00 00 00 00    ???.?????.......
10: e0 00 00 f0 00 00 03 00 00 7f 00 00 00 00 00 00    ?..?..?..?......
20: 7f 0a 01 00 00 XX 00 00 00 00 0e 00 00 00 40 00    ???..X....?...@.
30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 00    ..............U.
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Guenter Roeck June 18, 2016, 3:16 p.m. UTC | #3
Hi Andrew,

On 06/17/2016 04:21 PM, Andrew F. Davis wrote:
> On 06/10/2016 11:44 AM, Guenter Roeck wrote:
>> On Fri, Jun 10, 2016 at 10:32:33AM -0500, Andrew F. Davis wrote:
>>> Add support for the the INA3221 26v capable, Triple channel,
>>> Bi-Directional, Zero-Drift, Low-/High-Side, Current/Voltage Monitor
>>> with I2C interface.
>>>
>>> Signed-off-by: Andrew F. Davis <afd@ti.com>
>>
>> Applied to -next.
>>
>> Can you by any chance send me a register dump ? I would like to write
>> module test code for the chip.
>>
>
> No problem:
>
> # i2cdump -y 2 0x48
> No size specified (using byte-data access)
>       0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
> 00: 18 16 80 00 08 7f 80 7f 80 00 00 00 00 00 00 00    ???.?????.......
> 10: e0 00 00 f0 00 00 03 00 00 7f 00 00 00 00 00 00    ?..?..?..?......
> 20: 7f 0a 01 00 00 XX 00 00 00 00 0e 00 00 00 40 00    ???..X....?...@.
> 30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
> 40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
> 50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
> 60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
> 70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
> 80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
> 90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
> a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
> b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
> c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
> d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
> e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
> f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 00    ..............U.

The chip registers are 16 bit. Can you repeat the command using the "w" option ?

Thanks,
Guenter

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Andrew Davis June 24, 2016, 3:02 p.m. UTC | #4
On 06/18/2016 10:16 AM, Guenter Roeck wrote:
>
> The chip registers are 16 bit. Can you repeat the command using the "w"
> option ?
> 

# i2cdump -y 2 0x40 w
     0,8  1,9  2,a  3,b  4,c  5,d  6,e  7,f
00: 2771 0000 0000 0000 0000 0000 0000 f87f
08: f87f f87f f87f f87f f87f 0000 fe7f 0300
10: 1027 2823 ffff ffff ffff ffff ffff ffff
18: ffff ffff XXXX f8f8 ffff ffff 4954 2032
20: 2771 0000 0000 0000 0000 0000 0000 f87f
28: f87f f87f f87f f87f f87f 0000 fe7f 0300
30: 1027 2823 ffff ffff ffff ffff ffff ffff
38: ffff ffff XXXX f8f8 ffff ffff 4954 2032
40: 2771 0000 0000 0000 0000 0000 0000 f87f
48: f87f f87f f87f f87f f87f 0000 fe7f 0300
50: 1027 2823 ffff ffff ffff ffff ffff ffff
58: ffff ffff XXXX f8f8 ffff ffff 4954 2032
60: 2771 0000 0000 0000 0000 0000 0000 f87f
68: f87f f87f f87f f87f f87f 0000 fe7f 0300
70: 1027 2823 ffff ffff ffff ffff ffff ffff
78: ffff ffff XXXX f8f8 ffff ffff 4954 2032
80: 2771 0000 0000 0000 0000 0000 0000 f87f
88: f87f f87f f87f f87f f87f 0000 fe7f 0300
90: 1027 2823 ffff ffff ffff ffff ffff ffff
98: ffff ffff XXXX f8f8 ffff ffff 4954 2032
a0: 2771 0000 0000 0000 0000 0000 0000 f87f
a8: f87f f87f f87f f87f f87f 0000 fe7f 0300
b0: 1027 2823 ffff ffff ffff ffff ffff ffff
b8: ffff ffff XXXX f8f8 ffff ffff 4954 2032
c0: 2771 0000 0000 0000 0000 0000 0000 f87f
c8: f87f f87f f87f f87f f87f 0000 fe7f 0300
d0: 1027 2823 ffff ffff ffff ffff ffff ffff
d8: ffff ffff XXXX f8f8 ffff ffff 4954 2032
e0: 2771 0000 0000 0000 0000 0000 0000 f87f
e8: f87f f87f f87f f87f f87f 0000 fe7f 0300
f0: 1027 2823 ffff ffff ffff ffff ffff ffff
f8: ffff ffff XXXX f8f8 ffff ffff 4954 2032
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Guenter Roeck June 24, 2016, 4:46 p.m. UTC | #5
On Fri, Jun 24, 2016 at 10:02:51AM -0500, Andrew F. Davis wrote:
> On 06/18/2016 10:16 AM, Guenter Roeck wrote:
> >
> > The chip registers are 16 bit. Can you repeat the command using the "w"
> > option ?
> > 
> 
> # i2cdump -y 2 0x40 w
>      0,8  1,9  2,a  3,b  4,c  5,d  6,e  7,f
> 00: 2771 0000 0000 0000 0000 0000 0000 f87f
> 08: f87f f87f f87f f87f f87f 0000 fe7f 0300
> 10: 1027 2823 ffff ffff ffff ffff ffff ffff
> 18: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> 20: 2771 0000 0000 0000 0000 0000 0000 f87f
> 28: f87f f87f f87f f87f f87f 0000 fe7f 0300
> 30: 1027 2823 ffff ffff ffff ffff ffff ffff
> 38: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> 40: 2771 0000 0000 0000 0000 0000 0000 f87f
> 48: f87f f87f f87f f87f f87f 0000 fe7f 0300
> 50: 1027 2823 ffff ffff ffff ffff ffff ffff
> 58: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> 60: 2771 0000 0000 0000 0000 0000 0000 f87f
> 68: f87f f87f f87f f87f f87f 0000 fe7f 0300
> 70: 1027 2823 ffff ffff ffff ffff ffff ffff
> 78: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> 80: 2771 0000 0000 0000 0000 0000 0000 f87f
> 88: f87f f87f f87f f87f f87f 0000 fe7f 0300
> 90: 1027 2823 ffff ffff ffff ffff ffff ffff
> 98: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> a0: 2771 0000 0000 0000 0000 0000 0000 f87f
> a8: f87f f87f f87f f87f f87f 0000 fe7f 0300
> b0: 1027 2823 ffff ffff ffff ffff ffff ffff
> b8: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> c0: 2771 0000 0000 0000 0000 0000 0000 f87f
> c8: f87f f87f f87f f87f f87f 0000 fe7f 0300
> d0: 1027 2823 ffff ffff ffff ffff ffff ffff
> d8: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> e0: 2771 0000 0000 0000 0000 0000 0000 f87f
> e8: f87f f87f f87f f87f f87f 0000 fe7f 0300
> f0: 1027 2823 ffff ffff ffff ffff ffff ffff
> f8: ffff ffff XXXX f8f8 ffff ffff 4954 2032

Thanks a lot!

Guenter
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Andrew Davis June 24, 2016, 5:30 p.m. UTC | #6
On 06/24/2016 11:46 AM, Guenter Roeck wrote:
> On Fri, Jun 24, 2016 at 10:02:51AM -0500, Andrew F. Davis wrote:
>> On 06/18/2016 10:16 AM, Guenter Roeck wrote:
>>>
>>> The chip registers are 16 bit. Can you repeat the command using the "w"
>>> option ?
>>>
>>
>> # i2cdump -y 2 0x40 w
>>      0,8  1,9  2,a  3,b  4,c  5,d  6,e  7,f
>> 00: 2771 0000 0000 0000 0000 0000 0000 f87f
>> 08: f87f f87f f87f f87f f87f 0000 fe7f 0300
>> 10: 1027 2823 ffff ffff ffff ffff ffff ffff
>> 18: ffff ffff XXXX f8f8 ffff ffff 4954 2032
>> 20: 2771 0000 0000 0000 0000 0000 0000 f87f
>> 28: f87f f87f f87f f87f f87f 0000 fe7f 0300
>> 30: 1027 2823 ffff ffff ffff ffff ffff ffff
>> 38: ffff ffff XXXX f8f8 ffff ffff 4954 2032
>> 40: 2771 0000 0000 0000 0000 0000 0000 f87f
>> 48: f87f f87f f87f f87f f87f 0000 fe7f 0300
>> 50: 1027 2823 ffff ffff ffff ffff ffff ffff
>> 58: ffff ffff XXXX f8f8 ffff ffff 4954 2032
>> 60: 2771 0000 0000 0000 0000 0000 0000 f87f
>> 68: f87f f87f f87f f87f f87f 0000 fe7f 0300
>> 70: 1027 2823 ffff ffff ffff ffff ffff ffff
>> 78: ffff ffff XXXX f8f8 ffff ffff 4954 2032
>> 80: 2771 0000 0000 0000 0000 0000 0000 f87f
>> 88: f87f f87f f87f f87f f87f 0000 fe7f 0300
>> 90: 1027 2823 ffff ffff ffff ffff ffff ffff
>> 98: ffff ffff XXXX f8f8 ffff ffff 4954 2032
>> a0: 2771 0000 0000 0000 0000 0000 0000 f87f
>> a8: f87f f87f f87f f87f f87f 0000 fe7f 0300
>> b0: 1027 2823 ffff ffff ffff ffff ffff ffff
>> b8: ffff ffff XXXX f8f8 ffff ffff 4954 2032
>> c0: 2771 0000 0000 0000 0000 0000 0000 f87f
>> c8: f87f f87f f87f f87f f87f 0000 fe7f 0300
>> d0: 1027 2823 ffff ffff ffff ffff ffff ffff
>> d8: ffff ffff XXXX f8f8 ffff ffff 4954 2032
>> e0: 2771 0000 0000 0000 0000 0000 0000 f87f
>> e8: f87f f87f f87f f87f f87f 0000 fe7f 0300
>> f0: 1027 2823 ffff ffff ffff ffff ffff ffff
>> f8: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> 
> Thanks a lot!
> 

Feel free to completely ignore the first register dump I sent, I did it
for the wrong device anyway :).

I had just gotten done reading this:
https://lkml.org/lkml/2015/12/10/459
and accidentally got EVMs confused did the test for the TMP461, but it
does look like on startup register 0x16 can be used to differentiate the
parts, if the TMP461 hadn't gone into a different driver.

Andrew
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Guenter Roeck June 24, 2016, 8:19 p.m. UTC | #7
On Fri, Jun 24, 2016 at 12:30:56PM -0500, Andrew F. Davis wrote:
> On 06/24/2016 11:46 AM, Guenter Roeck wrote:
> > On Fri, Jun 24, 2016 at 10:02:51AM -0500, Andrew F. Davis wrote:
> >> On 06/18/2016 10:16 AM, Guenter Roeck wrote:
> >>>
> >>> The chip registers are 16 bit. Can you repeat the command using the "w"
> >>> option ?
> >>>
> >>
> >> # i2cdump -y 2 0x40 w
> >>      0,8  1,9  2,a  3,b  4,c  5,d  6,e  7,f
> >> 00: 2771 0000 0000 0000 0000 0000 0000 f87f
> >> 08: f87f f87f f87f f87f f87f 0000 fe7f 0300
> >> 10: 1027 2823 ffff ffff ffff ffff ffff ffff
> >> 18: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> >> 20: 2771 0000 0000 0000 0000 0000 0000 f87f
> >> 28: f87f f87f f87f f87f f87f 0000 fe7f 0300
> >> 30: 1027 2823 ffff ffff ffff ffff ffff ffff
> >> 38: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> >> 40: 2771 0000 0000 0000 0000 0000 0000 f87f
> >> 48: f87f f87f f87f f87f f87f 0000 fe7f 0300
> >> 50: 1027 2823 ffff ffff ffff ffff ffff ffff
> >> 58: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> >> 60: 2771 0000 0000 0000 0000 0000 0000 f87f
> >> 68: f87f f87f f87f f87f f87f 0000 fe7f 0300
> >> 70: 1027 2823 ffff ffff ffff ffff ffff ffff
> >> 78: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> >> 80: 2771 0000 0000 0000 0000 0000 0000 f87f
> >> 88: f87f f87f f87f f87f f87f 0000 fe7f 0300
> >> 90: 1027 2823 ffff ffff ffff ffff ffff ffff
> >> 98: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> >> a0: 2771 0000 0000 0000 0000 0000 0000 f87f
> >> a8: f87f f87f f87f f87f f87f 0000 fe7f 0300
> >> b0: 1027 2823 ffff ffff ffff ffff ffff ffff
> >> b8: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> >> c0: 2771 0000 0000 0000 0000 0000 0000 f87f
> >> c8: f87f f87f f87f f87f f87f 0000 fe7f 0300
> >> d0: 1027 2823 ffff ffff ffff ffff ffff ffff
> >> d8: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> >> e0: 2771 0000 0000 0000 0000 0000 0000 f87f
> >> e8: f87f f87f f87f f87f f87f 0000 fe7f 0300
> >> f0: 1027 2823 ffff ffff ffff ffff ffff ffff
> >> f8: ffff ffff XXXX f8f8 ffff ffff 4954 2032
> > 
> > Thanks a lot!
> > 
> 
> Feel free to completely ignore the first register dump I sent, I did it
> for the wrong device anyway :).
> 
> I had just gotten done reading this:
> https://lkml.org/lkml/2015/12/10/459
> and accidentally got EVMs confused did the test for the TMP461, but it
> does look like on startup register 0x16 can be used to differentiate the
> parts, if the TMP461 hadn't gone into a different driver.
> 
Good catch.

That makes me wonder if we should move tmp461 support to the lm90 driver.
What do you think ? Problem is that tmp461 will be auto-detected as tmp451
by the lm90 driver, which is less than perfect.

My test script for ina3221 only accepts a single value - 16380 - for the
limit registers. Seems odd. I'll have to look into it some more.

Guenter
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diff mbox

Patch

diff --git a/Documentation/hwmon/ina3221 b/Documentation/hwmon/ina3221
new file mode 100644
index 0000000..0ff7485
--- /dev/null
+++ b/Documentation/hwmon/ina3221
@@ -0,0 +1,35 @@ 
+Kernel driver ina3221
+=====================
+
+Supported chips:
+  * Texas Instruments INA3221
+    Prefix: 'ina3221'
+    Addresses: I2C 0x40 - 0x43
+    Datasheet: Publicly available at the Texas Instruments website
+               http://www.ti.com/
+
+Author: Andrew F. Davis <afd@ti.com>
+
+Description
+-----------
+
+The Texas Instruments INA3221 monitors voltage, current, and power on the high
+side of up to three D.C. power supplies. The INA3221 monitors both shunt drop
+and supply voltage, with programmable conversion times and averaging, current
+and power are calculated host-side from these.
+
+Sysfs entries
+-------------
+
+in[123]_input           Bus voltage(mV) channels
+curr[123]_input         Current(mA) measurement channels
+shunt[123]_resistor     Shunt resistance(uOhm) channels
+curr[123]_crit          Critical alert current(mA) setting, activates the
+                          corresponding alarm when the respective current
+                          is above this value
+curr[123]_crit_alarm    Critical alert current limit exceeded
+curr[123]_max           Warning alert current(mA) setting, activates the
+                          corresponding alarm when the respective current
+                          average is above this value.
+curr[123]_max_alarm     Warning alert current limit exceeded
+in[456]_input           Shunt voltage(uV) for channels 1, 2, and 3 respectively
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index ff94007..e924d16 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1514,6 +1514,17 @@  config SENSORS_INA2XX
 	  This driver can also be built as a module.  If so, the module
 	  will be called ina2xx.
 
+config SENSORS_INA3221
+	tristate "Texas Instruments INA3221 Triple Power Monitor"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  If you say yes here you get support for  the TI INA3221 Triple Power
+	  Monitor.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called ina3221.
+
 config SENSORS_TC74
 	tristate "Microchip TC74"
 	depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 2ef5b7c..91da96a 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -77,6 +77,7 @@  obj-$(CONFIG_SENSORS_IBMPOWERNV)+= ibmpowernv.o
 obj-$(CONFIG_SENSORS_IIO_HWMON) += iio_hwmon.o
 obj-$(CONFIG_SENSORS_INA209)	+= ina209.o
 obj-$(CONFIG_SENSORS_INA2XX)	+= ina2xx.o
+obj-$(CONFIG_SENSORS_INA3221)	+= ina3221.o
 obj-$(CONFIG_SENSORS_IT87)	+= it87.o
 obj-$(CONFIG_SENSORS_JC42)	+= jc42.o
 obj-$(CONFIG_SENSORS_JZ4740)	+= jz4740-hwmon.o
diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
new file mode 100644
index 0000000..d055b6a
--- /dev/null
+++ b/drivers/hwmon/ina3221.c
@@ -0,0 +1,446 @@ 
+/*
+ * INA3221 Triple Current/Voltage Monitor
+ *
+ * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
+ *	Andrew F. Davis <afd@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+
+#define INA3221_DRIVER_NAME		"ina3221"
+
+#define INA3221_CONFIG			0x00
+#define INA3221_SHUNT1			0x01
+#define INA3221_BUS1			0x02
+#define INA3221_SHUNT2			0x03
+#define INA3221_BUS2			0x04
+#define INA3221_SHUNT3			0x05
+#define INA3221_BUS3			0x06
+#define INA3221_CRIT1			0x07
+#define INA3221_WARN1			0x08
+#define INA3221_CRIT2			0x09
+#define INA3221_WARN2			0x0a
+#define INA3221_CRIT3			0x0b
+#define INA3221_WARN3			0x0c
+#define INA3221_MASK_ENABLE		0x0f
+
+#define INA3221_CONFIG_MODE_SHUNT	BIT(1)
+#define INA3221_CONFIG_MODE_BUS		BIT(2)
+#define INA3221_CONFIG_MODE_CONTINUOUS	BIT(3)
+
+#define INA3221_RSHUNT_DEFAULT		10000
+
+enum ina3221_fields {
+	/* Configuration */
+	F_RST,
+
+	/* Alert Flags */
+	F_WF3, F_WF2, F_WF1,
+	F_CF3, F_CF2, F_CF1,
+
+	/* sentinel */
+	F_MAX_FIELDS
+};
+
+static const struct reg_field ina3221_reg_fields[] = {
+	[F_RST] = REG_FIELD(INA3221_CONFIG, 15, 15),
+
+	[F_WF3] = REG_FIELD(INA3221_MASK_ENABLE, 3, 3),
+	[F_WF2] = REG_FIELD(INA3221_MASK_ENABLE, 4, 4),
+	[F_WF1] = REG_FIELD(INA3221_MASK_ENABLE, 5, 5),
+	[F_CF3] = REG_FIELD(INA3221_MASK_ENABLE, 7, 7),
+	[F_CF2] = REG_FIELD(INA3221_MASK_ENABLE, 8, 8),
+	[F_CF1] = REG_FIELD(INA3221_MASK_ENABLE, 9, 9),
+};
+
+enum ina3221_channels {
+	INA3221_CHANNEL1,
+	INA3221_CHANNEL2,
+	INA3221_CHANNEL3,
+	INA3221_NUM_CHANNELS
+};
+
+static const unsigned int register_channel[] = {
+	[INA3221_SHUNT1] = INA3221_CHANNEL1,
+	[INA3221_SHUNT2] = INA3221_CHANNEL2,
+	[INA3221_SHUNT3] = INA3221_CHANNEL3,
+	[INA3221_CRIT1] = INA3221_CHANNEL1,
+	[INA3221_CRIT2] = INA3221_CHANNEL2,
+	[INA3221_CRIT3] = INA3221_CHANNEL3,
+	[INA3221_WARN1] = INA3221_CHANNEL1,
+	[INA3221_WARN2] = INA3221_CHANNEL2,
+	[INA3221_WARN3] = INA3221_CHANNEL3,
+};
+
+/**
+ * struct ina3221_data - device specific information
+ * @regmap: Register map of the device
+ * @fields: Register fields of the device
+ * @shunt_resistors: Array of resistor values per channel
+ */
+struct ina3221_data {
+	struct regmap *regmap;
+	struct regmap_field *fields[F_MAX_FIELDS];
+	unsigned int shunt_resistors[INA3221_NUM_CHANNELS];
+};
+
+static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
+			      int *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(ina->regmap, reg, &regval);
+	if (ret)
+		return ret;
+
+	*val = sign_extend32(regval >> 3, 12);
+
+	return 0;
+}
+
+static ssize_t ina3221_show_bus_voltage(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	unsigned int reg = sd_attr->index;
+	int val, voltage_mv, ret;
+
+	ret = ina3221_read_value(ina, reg, &val);
+	if (ret)
+		return ret;
+
+	voltage_mv = val * 8;
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", voltage_mv);
+}
+
+static ssize_t ina3221_show_shunt_voltage(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	unsigned int reg = sd_attr->index;
+	int val, voltage_uv, ret;
+
+	ret = ina3221_read_value(ina, reg, &val);
+	if (ret)
+		return ret;
+	voltage_uv = val * 40;
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", voltage_uv);
+}
+
+static ssize_t ina3221_show_current(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	unsigned int reg = sd_attr->index;
+	unsigned int channel = register_channel[reg];
+	unsigned int resistance_uo = ina->shunt_resistors[channel];
+	int val, current_ma, voltage_nv, ret;
+
+	ret = ina3221_read_value(ina, reg, &val);
+	if (ret)
+		return ret;
+	voltage_nv = val * 40000;
+
+	current_ma = DIV_ROUND_CLOSEST(voltage_nv, resistance_uo);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", current_ma);
+}
+
+static ssize_t ina3221_set_current(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t count)
+{
+	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	unsigned int reg = sd_attr->index;
+	unsigned int channel = register_channel[reg];
+	unsigned int resistance_uo = ina->shunt_resistors[channel];
+	int val, current_ma, voltage_uv, ret;
+
+	ret = kstrtoint(buf, 0, &current_ma);
+	if (ret)
+		return ret;
+
+	/* clamp current */
+	current_ma = clamp_val(current_ma,
+			       INT_MIN / resistance_uo,
+			       INT_MAX / resistance_uo);
+
+	voltage_uv = DIV_ROUND_CLOSEST(current_ma * resistance_uo, 1000);
+
+	/* clamp voltage */
+	voltage_uv = clamp_val(voltage_uv, -163800, 163800);
+
+	/* 1 / 40uV(scale) << 3(register shift) = 5 */
+	val = DIV_ROUND_CLOSEST(voltage_uv, 5) & 0xfff8;
+
+	ret = regmap_write(ina->regmap, reg, val);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t ina3221_show_shunt(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	unsigned int channel = sd_attr->index;
+	unsigned int resistance_uo;
+
+	resistance_uo = ina->shunt_resistors[channel];
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", resistance_uo);
+}
+
+static ssize_t ina3221_set_shunt(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t count)
+{
+	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	unsigned int channel = sd_attr->index;
+	unsigned int val;
+	int ret;
+
+	ret = kstrtouint(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	if (val == 0)
+		return -EINVAL;
+
+	ina->shunt_resistors[channel] = val;
+
+	return count;
+}
+
+static ssize_t ina3221_show_alert(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	unsigned int field = sd_attr->index;
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_field_read(ina->fields[field], &regval);
+	if (ret)
+		return ret;
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", regval);
+}
+
+/* bus voltage */
+static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO,
+		ina3221_show_bus_voltage, NULL, INA3221_BUS1);
+static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO,
+		ina3221_show_bus_voltage, NULL, INA3221_BUS2);
+static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO,
+		ina3221_show_bus_voltage, NULL, INA3221_BUS3);
+
+/* calculated current */
+static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO,
+		ina3221_show_current, NULL, INA3221_SHUNT1);
+static SENSOR_DEVICE_ATTR(curr2_input, S_IRUGO,
+		ina3221_show_current, NULL, INA3221_SHUNT2);
+static SENSOR_DEVICE_ATTR(curr3_input, S_IRUGO,
+		ina3221_show_current, NULL, INA3221_SHUNT3);
+
+/* shunt resistance */
+static SENSOR_DEVICE_ATTR(shunt1_resistor, S_IRUGO | S_IWUSR,
+		ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL1);
+static SENSOR_DEVICE_ATTR(shunt2_resistor, S_IRUGO | S_IWUSR,
+		ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL2);
+static SENSOR_DEVICE_ATTR(shunt3_resistor, S_IRUGO | S_IWUSR,
+		ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL3);
+
+/* critical current */
+static SENSOR_DEVICE_ATTR(curr1_crit, S_IRUGO | S_IWUSR,
+		ina3221_show_current, ina3221_set_current, INA3221_CRIT1);
+static SENSOR_DEVICE_ATTR(curr2_crit, S_IRUGO | S_IWUSR,
+		ina3221_show_current, ina3221_set_current, INA3221_CRIT2);
+static SENSOR_DEVICE_ATTR(curr3_crit, S_IRUGO | S_IWUSR,
+		ina3221_show_current, ina3221_set_current, INA3221_CRIT3);
+
+/* critical current alert */
+static SENSOR_DEVICE_ATTR(curr1_crit_alarm, S_IRUGO,
+		ina3221_show_alert, NULL, F_CF1);
+static SENSOR_DEVICE_ATTR(curr2_crit_alarm, S_IRUGO,
+		ina3221_show_alert, NULL, F_CF2);
+static SENSOR_DEVICE_ATTR(curr3_crit_alarm, S_IRUGO,
+		ina3221_show_alert, NULL, F_CF3);
+
+/* warning current */
+static SENSOR_DEVICE_ATTR(curr1_max, S_IRUGO | S_IWUSR,
+		ina3221_show_current, ina3221_set_current, INA3221_WARN1);
+static SENSOR_DEVICE_ATTR(curr2_max, S_IRUGO | S_IWUSR,
+		ina3221_show_current, ina3221_set_current, INA3221_WARN2);
+static SENSOR_DEVICE_ATTR(curr3_max, S_IRUGO | S_IWUSR,
+		ina3221_show_current, ina3221_set_current, INA3221_WARN3);
+
+/* warning current alert */
+static SENSOR_DEVICE_ATTR(curr1_max_alarm, S_IRUGO,
+		ina3221_show_alert, NULL, F_WF1);
+static SENSOR_DEVICE_ATTR(curr2_max_alarm, S_IRUGO,
+		ina3221_show_alert, NULL, F_WF2);
+static SENSOR_DEVICE_ATTR(curr3_max_alarm, S_IRUGO,
+		ina3221_show_alert, NULL, F_WF3);
+
+/* shunt voltage */
+static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO,
+		ina3221_show_shunt_voltage, NULL, INA3221_SHUNT1);
+static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO,
+		ina3221_show_shunt_voltage, NULL, INA3221_SHUNT2);
+static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO,
+		ina3221_show_shunt_voltage, NULL, INA3221_SHUNT3);
+
+static struct attribute *ina3221_attrs[] = {
+	/* channel 1 */
+	&sensor_dev_attr_in1_input.dev_attr.attr,
+	&sensor_dev_attr_curr1_input.dev_attr.attr,
+	&sensor_dev_attr_shunt1_resistor.dev_attr.attr,
+	&sensor_dev_attr_curr1_crit.dev_attr.attr,
+	&sensor_dev_attr_curr1_crit_alarm.dev_attr.attr,
+	&sensor_dev_attr_curr1_max.dev_attr.attr,
+	&sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
+	&sensor_dev_attr_in4_input.dev_attr.attr,
+
+	/* channel 2 */
+	&sensor_dev_attr_in2_input.dev_attr.attr,
+	&sensor_dev_attr_curr2_input.dev_attr.attr,
+	&sensor_dev_attr_shunt2_resistor.dev_attr.attr,
+	&sensor_dev_attr_curr2_crit.dev_attr.attr,
+	&sensor_dev_attr_curr2_crit_alarm.dev_attr.attr,
+	&sensor_dev_attr_curr2_max.dev_attr.attr,
+	&sensor_dev_attr_curr2_max_alarm.dev_attr.attr,
+	&sensor_dev_attr_in5_input.dev_attr.attr,
+
+	/* channel 3 */
+	&sensor_dev_attr_in3_input.dev_attr.attr,
+	&sensor_dev_attr_curr3_input.dev_attr.attr,
+	&sensor_dev_attr_shunt3_resistor.dev_attr.attr,
+	&sensor_dev_attr_curr3_crit.dev_attr.attr,
+	&sensor_dev_attr_curr3_crit_alarm.dev_attr.attr,
+	&sensor_dev_attr_curr3_max.dev_attr.attr,
+	&sensor_dev_attr_curr3_max_alarm.dev_attr.attr,
+	&sensor_dev_attr_in6_input.dev_attr.attr,
+
+	NULL,
+};
+ATTRIBUTE_GROUPS(ina3221);
+
+static const struct regmap_range ina3221_yes_ranges[] = {
+	regmap_reg_range(INA3221_SHUNT1, INA3221_BUS3),
+	regmap_reg_range(INA3221_MASK_ENABLE, INA3221_MASK_ENABLE),
+};
+
+static const struct regmap_access_table ina3221_volatile_table = {
+	.yes_ranges = ina3221_yes_ranges,
+	.n_yes_ranges = ARRAY_SIZE(ina3221_yes_ranges),
+};
+
+static const struct regmap_config ina3221_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 16,
+
+	.cache_type = REGCACHE_RBTREE,
+	.volatile_table = &ina3221_volatile_table,
+};
+
+static int ina3221_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct ina3221_data *ina;
+	struct device *hwmon_dev;
+	int i, ret;
+
+	ina = devm_kzalloc(dev, sizeof(*ina), GFP_KERNEL);
+	if (!ina)
+		return -ENOMEM;
+
+	ina->regmap = devm_regmap_init_i2c(client, &ina3221_regmap_config);
+	if (IS_ERR(ina->regmap)) {
+		dev_err(dev, "Unable to allocate register map\n");
+		return PTR_ERR(ina->regmap);
+	}
+
+	for (i = 0; i < F_MAX_FIELDS; i++) {
+		ina->fields[i] = devm_regmap_field_alloc(dev,
+							 ina->regmap,
+							 ina3221_reg_fields[i]);
+		if (IS_ERR(ina->fields[i])) {
+			dev_err(dev, "Unable to allocate regmap fields\n");
+			return PTR_ERR(ina->fields[i]);
+		}
+	}
+
+	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
+		ina->shunt_resistors[i] = INA3221_RSHUNT_DEFAULT;
+
+	ret = regmap_field_write(ina->fields[F_RST], true);
+	if (ret) {
+		dev_err(dev, "Unable to reset device\n");
+		return ret;
+	}
+
+	hwmon_dev = devm_hwmon_device_register_with_groups(dev,
+							   client->name,
+							   ina, ina3221_groups);
+	if (IS_ERR(hwmon_dev)) {
+		dev_err(dev, "Unable to register hwmon device\n");
+		return PTR_ERR(hwmon_dev);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id ina3221_of_match_table[] = {
+	{ .compatible = "ti,ina3221", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ina3221_of_match_table);
+
+static const struct i2c_device_id ina3221_ids[] = {
+	{ "ina3221", 0 },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, ina3221_ids);
+
+static struct i2c_driver ina3221_i2c_driver = {
+	.probe = ina3221_probe,
+	.driver = {
+		.name = INA3221_DRIVER_NAME,
+		.of_match_table = ina3221_of_match_table,
+	},
+	.id_table = ina3221_ids,
+};
+module_i2c_driver(ina3221_i2c_driver);
+
+MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
+MODULE_DESCRIPTION("Texas Instruments INA3221 HWMon Driver");
+MODULE_LICENSE("GPL v2");